En EspaŅol

Q. Who is Mr. Smarty Plants?

A: There are those who suspect Wildflower Center volunteers are the culpable and capable culprits. Yet, others think staff members play some, albeit small, role. You can torture us with your plant questions, but we will never reveal the Green Guru's secret identity.

Help us grow by giving to the Plant Database Fund or by becoming a member

Did you know you can access the Native Plant Information Network with your web-enabled smartphone?

Share

Ask Mr. Smarty Plants

Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.

Search Smarty Plants
    
 
See a list of all Smarty Plants questions
Can't find the answer in our existing FAQs, submit a question to Mr. Smarty Plants.
Need help with plant identification, visit the plant identification page.
 
rate this answer
Not Yet Rated

Thursday - September 06, 2012

From: San Antonio, TX
Region: Southwest
Topic: Diseases and Disorders, Trees
Title: Sap dripping from a lacey oaks in San Antonio
Answered by: Barbara Medford

QUESTION:

I have a lacey oak tree, approximately 6 ft. tall that has been in the ground almost a year. The tree looks healthy but there is a small area on the trunk that looks and feels wet. The substance is sticky and appears to be sap oozing from the tree. The area is approx. 8 inches long on one side of the trunk starting under a nub where a small branch was removed a few months ago. The area is about 1 1/2 - 2 ft. off the ground. Is this something I should be concerned about?

ANSWER:

Yes. If you follow this plant link Quercus laceyi (Lacey oak) to our webpage on this tree, you will learn that it is very popular in Central Texas because it is more oak wilt resistant than the red oak Quercus buckleyi (Texas red oak) or Quercus fusiformis (Escarpment live oak). The fact that the ooze is near a "nub" where a branch has been removed is another clue. Unfortunately, "oak wilt resistant" is not "oak wilt immune;" just as "deer resistant" is not "deer proof."

So, we need to ask a couple of rhetorical questions. Was that branch removed between November and January? And was the wound painted with pruning paint? There is this little beast called a nitidulid beetle who is very fond of oak sap. The only way he can get at the sap is if something (pruning, weedeater, lawnmower) breaks the bark and the sap begins to ooze out. He is not active in the coldest months of the year, so that is when we recommend any pruning to an oak be done. We also recommend that if any branch bigger around than your thumb is pruned the wound be covered immediately in pruning paint.

And why is this little beetle so scary? Because we have wide-spread infestations of Oak Wilt in Central Texas. When sap is draining from an infected tree, the beetle (who doesn't harm the tree at all) comes along and has a snack, he will probably take away some of the fungus from the Oak Wilt, and generously share it with the next tree he visits. In addition, infection can sometimes pass from one oak to another via roots, which means you need to act quickly to save other oaks around that tree from infection that way.

Please go to this website Texas Oak Wilt.org. and read all of it. It can give you the information you need much better than we can. On that Home Page, click on Get Help. Next, we would direct you to the page on Texas Agrilife Cooperative Extension. There you will see a map indicating that Bexar County does have Oak Wilt present and that there are experts to help you. Start with the Texas Agrilife Extension Service Office for Bexar County. Alternatively, you can go to the Texas Forest Service. Bexar County is in the Kerrville District, so scroll down the Forest Service page to the Kerrville District, where you will find the contact information you need.

We urge you not to delay in taking care of this problem. The tree is so young and small,  the experts may recommend taking it out and destroying it before the contagion can spread. Take their advice on when and how to take it out and when it will be safe to replace it. Remember: we recommend that all woody plants, trees and shrubs be planted in November to January, when they are dormant. This applies to any woody plants, not just those prone to Oak Wilt.

 

 

From the Image Gallery


Lacey oak
Quercus laceyi

Texas red oak
Quercus buckleyi

Escarpment live oak
Quercus fusiformis

More Diseases and Disorders Questions

Mountain laurel (Sophora secundiflora) refuses to bloom
March 07, 2008 - We have a Texas Mountain Laurel that gets full sunlight, but does not bloom. It is 4-5 ft tall & 3-4 ft wide & healthy. Is there anything we can do to make it bloom next year?
view the full question and answer

Growth on top of Echinacea purpurea (Eastern purple coneflower)
July 03, 2012 - I grow purple coneflowers in my garden. ONE plant has something growing on the top of each cone. I would like to know what it is but I don't see how I can add a photo to this post.
view the full question and answer

Improving blooming on mock orange
March 03, 2008 - I have a now 6 yr. old mock orange shrub in the garden which has never bloomed, darn it. I have fed, not fed, mulched, not mulched, sheared, not sheared. What gives? Will it ever bloom, or shall I ...
view the full question and answer

Need help controling suckers from an ornamental plum in San Pedro, CA.
August 10, 2010 - I have an ornamental plum tree in my garden which produces a lot of suckers in my vegetable beds. I do not want to use harmful chemicals and cutting them back is a hopeless venture and leaves small...
view the full question and answer

Live oak with brown balls and brown spots in Round Rock PA
August 01, 2010 - Is my live oak sick? Brown spots are on the leaves and round brown balls are growing on the stems. Please help.
view the full question and answer

Smarty Plants's Facebook profile Support the Wildflower Center by Donating Online or Becoming a Member today.

Mr. Smarty Plants wants you to be his Facebook friend. Click the Facebook icon to add yourself to Mr. Smarty Plants list of friends.
E-NEWSLETTER | BECOME A MEMBER | DONATE NOW | MEDIA | SITEMAP
© 2014 Lady Bird Johnson Wildflower Center